More Melthole Mania

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This morning we finally got ENDURANCE all weighted properly and had finished up all the melting that we wanted to do to finish out the melthole. We were excited to finally get the ‘bot out to do some missions. We went through our launch checklist, got the ‘bot in the water, and placed the dive weight on top which lets ENDURANCE descend the melthole without churning the water too much with its thrusters. Bill was manning the line tied to the dive weight, getting ready to pull it off when ENDURANCE reached its transit depth under the ice. Suddenly, he said “it’s stopped going down,” followed shortly “I wonder if it’s stuck.”
We all looked at each other. Could it be that there was still some protruding parts at the bottom of the melthole that wouldn’t let ENDURANCE pass? I got out the fish cam (a little waterproof camera/lights combo in the shape of a fish which you can drop on a cable and see what thing look like down below on a little TV monitor). Sure enough, when I guided the camera around the perimeter of the syntactic, you could see a little ledge that ENDURANCE was sitting on on one side, and where it was pushed up against the ice wall on the other. After all of the energy that went into it, the hole was still not quite done.
So, we fired up the Hotsies again. Bill and I went around the perimeter of the hole again to look at where to put the melting coils.

View of the Hotsy melting coil at the bottom of the melt hole from the fish cam. You can see the flange of ice that stopped ENDURANCE from going all the way down the hole in front of the coil as we attempt to melt it out.

When we got the Hotsy melt coils back in position, there wasn’t really much else for all of us to do.

Shilpa, Rachel and Chris at the control center area in the bothouse, waiting for the Hotsies to work.

After about 15 minutes, Bill came up with the idea that maybe he could go diving with the big ice chipper bar and attack the offending ice lips more effectively than trying to adjust the Hotsies from the surface. So he got kitted up and we dropped him into the melthole.

Bill being lowered into the melthole to perform melthole maintenance.

He managed to knock off some big chunks and smooth out some lumpy areas. Surprising how much he could get done given that he was dressed in an inflated dry suit, with “lobster mits” (the index finger is separate), and floating free in the water as he swung the chipper bar. But he did it! We quickly sent ENDURANCE all the way down the hole before the end of the day. It fit! We even had it move around a little under the ice of Lake Bonney to test out the navigation sensors and new software. Tomorrow, we should be able to do our calibration runs and then start gathering real data on Friday. As Chris would say: “Sweet.”

Bill discussing the results of his chipping with Bart while Vickie unzips the back of his drysuit.